Starter Battery Drains with House

[tdellaviola]

Hi I have a battery issue that I am hoping for some ideas. I have scanned older posts but don't see the same fit.
This is for a 2014 cutwater C30.
Has anybody had an issue where the Starter battery drains at the same rate as the house bank even though the join switch is off. While on anchor this last weekend, my starter battery consistently showed same voltage as the house bank. Starts out strong but by noon next day down at the 12.2 range. I have the join switch turned off and the starter turned off. Thruster battery does not deplete over night. It feels like the join switch has failed and is allowing the starter not to be isolated from house, even though starter switch is off.

Note: when the house switch is also off both house and starter retain their charge.

I have not dug into the batteries with voltage/amp meter yet, but thought I would check with the forum to see if anyone has had this issue.

 

[Red Raven]

Maybe the House/engine ACR has failed in the closed position?

Curt

 

[BB marine]

There are two common links to house and engine batteries. The parallel switch if on they are combined as a parallel circuit and the Charge relays are combined as a parallel circuit. ACRs are intended to distribute current from a charging source (engine) to all batteries, but leave the engine batteries isolated during discharge.The batteries are effectively connected together during charging and disconnected during discharge. The ACR close when the voltage on one of the batteries rises to a level normally 13.2V to 13.7V (from manual) and open when voltage decreases 12.4 to 13.1 (from manual) I have never experienced the house to stay connected as low as 12.4. It seems that when the engine is not running and the house battery is running 12V accessories or the inverter the disconnect happens around 12.75. I would suspect your ACR feeding your house battery from the engine battery may be staying close and allowing the house to stay connected to the engine battery. The thruster battery ACR seems to be opening properly. Just a guess but something look at, see if the green light is staying on. also check with a VOA meter to confirm that the relay is open when engine is off and house battery is in use. Make sure if your testing at the dock that the battery charger is turned off.

 

[Cutwater28GG]

my bets are ACR too- check out the LED as mentioned and see if its closely appropriately. but check for other parasitic draws on the start battery like the propane solenoid...

I have had the issue where the engine batt was down on volts over a couple of days on the anchor.
out of curiousity, did you have variable sunny/cloudy conditions? and swinging at anchor with a shadow regularily on the solar panel.?

the ACR's have a timeout where they stay open once the voltage threshold has been hit. its like 90 seconds from recollection.
I have a theory I am trying to test that with a regular swing at anchor the shadow on the solar panel keeps setting off the ACR to Open but then the batteries are drawn down before the ACR closes again. this keeps happening during the day and it means over the long turn that the ACR is effectively open and the engine batt is drawn down.
its magnified on my cutwater 28 as its a 2012 which had a more vertical tower which puts more shadow on the panel.

 

[bill46]

Check the parallel switch. should be off unless using house battery to start.
ACRs are very reliable.

 

[Duchscherer]

i hav had a similiar problem on my 2013 Cutwater 28, After a night at anchor, the engine battery was down and the engine needed the crossover switch on to start the engine. I did notice once that when having the anchor watch on the chart plotter overnight the fan runningon the chart plotter ran down the battery. Makes the anchor watch useless in my mind unless the engine is running. However, the engine batter was also down and hard to start after an overnight at anchor without running the anchor watch. Apprecited the comments from others but not being an battery expert what does the "ACR" mean. Is the best approach to just not use any batteries when at anchor??

 

[BB marine]

ACR is Auto Charging Relay https://www.google.com/url?sa=t&rct=j&q ... JDmd_mMZif

The Garmin chart plotter anchor watch should not run the battery down. I have run my inverter for my C-pap, 12V fan running in the V berth, anchor watch on, fridge running, and still had 12.5V in the morning

 

[snydzy]

Another answer may be ACR cycling....Blue Sea has an article here: https://www.bluesea.com/support/article ... ing_Relays
I experienced this same phenomenon, and discovered that the solar panel leads had been wired directly to both sides of the engine/house ACR. This caused my engine battery to discharge with the house bank. The fix was to wire the solar panel directly to the batteries. More information is here: https://marinehowto.com/automatic-charging-relays/
Be sure to watch the video at the end of the article.

 

[Cutwater28GG]

Epic. Thanks for sharing this article. I definitely have this behavior on the cutwater.

 

[Duchscherer]

where is the ACR located??

 

[Cutwater28GG]

for me its in the same location as the batteries mounted on the wall. on my boat this is all in the port locker. on newer boats the batteries are split into port and starboard lockers. I think the ACR's are still in the port locker

 

[Rubyp]

We were up in the north channel this summer same problem. R31S, At anchor, drain house batteries then in morning try to start engine. NOPE will not start, old AGM batteries 2016 ? starter battery draining on house loads ? NOPE OPERATOR ERROR! The propane solenoid valve to sequester propane off the boat draws about 1 amp per hour, it is wired to the starter battery per wiring diagram. The batteries tested 525 cca when removed so aging batteries, and leaving the propane switch on after using cooktop after dinner and all night drained the starter battery enough that would not start. Happened twice once the parallel switch saved me, last time solar panel saved me after 3hrs. Figured it out in marina and tested it twice engine started every time. :lol:

 

[tdellaviola]

Hello everyone, and thank you for all the replies to my original post. I have not 100% confirmed my issue with the starter battery being drained, but the posts on the propane solenoid being hooked to the starter battery sheds new light!!
I was not aware that the solenoid was on the starter or that it drew as much power. I always turned it on at the start of a trip but managed the actual propane using the physical valve on the tanks. I assumed it went off when I turned off the power to house.
I charged my batteries 2 weeks ago, then checked them on Sunday, all good except starter, it was so low it didn't register on gauges. Managed to get them charged Sunday thru Tuesday, disconnected charger. Checked Thursday, starter significantly drained.
Now with this new info on the solenoid being on the starter when I checked Thursday evening, I was really hoping the solenoid was left on as that would be my problem. It was not. BUT, I checked the physical solenoid switch on the tanks and it was HOT. So somehow it was getting power?? I switched the solenoid off and on a few times, confirmed that in the Off position propane was not getting by. Checked the physical switch this AM and it was cold.
I recharged the batteries last night, so will see if starter holds power now that the switch is for sure off and its not getting power.
Seem very odd that the switch in the mid-birth was OFF, yet the solenoid was hot? Electronics...…. arg!